William



(No Model.)

W. O. COMSTOCK. LINING FOR PULP DIGESTERS- No. 453,076. Patented May26,- 1891.

UNITED STATES PATENT OFFICE.

\VILLIAM O. COMSTOCK, OF NElV YORK,,N. Y.

LINING FOR PULP-DIGESTERS.

SPECIFICATION forming part of Letters Patent No. 453,076, dated May 26,1891.

Application filed November 12, 1890. Serial No. 371,149. (No model.)

To all whom-it may concern.-

Be itknownthat I, WILLIAM O. COMSTOOK, of New York, in the county andState of New York, have invented a new and useful Improvement in Liningfor Pulp-Digesters, of which the following is a full, clear, and exactdescription.

The invention relates to improvements in the lining for pulp-digestershaving walls of iron or steel 5 audit has for its objects to furnish anacid-proof sectional lining therefor, which by its formation andcomposition will be adapted to remain intact and acid-resistant when inservice and be non-liable to rupture at its joints, which might resultfrom a want of support for the several lining-sections or from unequalexpansion and contraction as compared to that of the shell.

To these ends my invention consists in the construction of the lining,its manner of support within the shell, and the use of a pecu' liarcombination of metals to produce said lining, whereby efficiency inservice is secured at a moderate cost for material and manufacture, asis hereinafter shown, described, and claimed.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure 1 is a side elevation in section of a principal portion of adigester-shell and its lining, showing improved means for the supportand attachment of the lining to the shell. Fig. 2 is a plan view insection of a shell, its lining, and supports for the lining, taken ontheline 2 2 in Fig. 1. Fig. 3 is an enlarged plan in section of aportion of the digester-shell and interior parts connected therewith,taken on the line 3 3 in Fig. 1. Fig. erepresents an enlarged brokensection, vertically taken, of a portion of the digester shell andinterior parts, showing the supports for-a lining-section, two sectionsat their adjacent edges, and means to seal the joints between thelining-sections and supports therefor, the view indicating a portion ofthe device opposite the arrow at in Fig. 1. Fig. 5is an enlargedvertical section of the digesterwall, the lining, and a supportingdevice for said lining, which also binds the lining and shell together,the section being taken on a lining of acid-resisting material or theline 5 5in Fig. 1. Fig. 6 is a View, enlarged, of a portion of thelining and securing device therefor, viewed in the direction of thearrow 6 in Fig. 5; and Fig. 7 is a detached vertical sectional view of aportion of the digester-cover, its lining, the digestershell, anangle-iron top ring on its exterior at the upper edge of the shell, alining-ring of alloy, a re-enforce ring, and a joint-covering ring.

The disintegration of wood in digesters to afford pulped fiber for themanufacture of paper requires a strong acid solution and the applicationof heat, and as the acid will corrode the iron or steel shell preferablyemployed to form the digester-chamber, and by the formation of rustdiscolor the paper-stock,

composition must be provided therefor.

Digester-chambers for wood pulping are made of considerable capacity.l-lenceitis desirable,in order to facilitate the manufacture of thelining, that it be made in several pieces or sections, which are ofproper form to fit in and completely coverv the interior surface of theexterior shell, and such sections must be joined so as to seal thepoints of junction to prevent leakage. An acid-proof lining for thepurpose indicated (to avoid injury to its body and preserve theintegrity of its joints) should be composed of material that will haveabout the same ratio of expansion and contraction when exposed tofluctuations of heat as are incidental to the iron or steel shell of thedigester, and each section of the lining should be independentlysupported from the shell, so as to avoid injury to lower sections of thelining when in service. The essential features which have been indicatedas necessary to secure the continued service and avoidance of injury tothe apparatus or product are embodied in the improved device,

which will now be specifically described.

The shell A of the digester-chamber is preferably made of iron or steelplate, as usual. The complete upper and lower portions of ordinaryformation are not shown, it being Well understood that the bottom of theshell is contracted to afford an exit-passage, that is sealed by anypreferred means, and the top of said shell closed by a cover whichisremovable,a portion of said cover being shown in Fig. *7. \Vithin theshell A A an acid-proof lining B is located, which is made of a metalliccomposition, the formulafor the preparation of said composite metalbeing hereinafter given. As shown in Fig. 1, the lower section of thelining B preferably rests upon the upper and inner edge 0t of the lappedportions of the shell A, where the conical bottom portion A of saidshell is joined by rivets to the upper cylindrical wall of the same, theedge a being the upper terminal of the bottom piece named. The lining ofthe bottom A overlaps the point of junction at, and at b is brazed orsoldered to the inner surface of the lining of the shell A, so that anacid-proof joint is there afforded which renders the bottom liningcontinuous with the lower lining section of the side wall, and, asshown, a joint-covering ring E is placed upon the lining of the bottom Aand shell A over the joint I), which ring is adapted to closely fit onthe joint and rest on the lining-sections, to which it is brazed orsoldered, forming acid-proof joints therewith. The lining of thedigester-shell A may be in the form of several cylindrical integralrings of suitable height, or, preferably, each liningring may becomposed of two or more separate pieces that have their vertical edgesin close contact, asshown at c in Fig. 2; or the vertical bars (I may beinterposed between the upright edges of the ring-sections, as shown inthe same figure. secured to the shell A,provide ledges against which thepieces of a ring B closely impinge. Any necessary number of lining-ringsB are provided to cover the interior of the shell A, and between theadjacent edges of two rings there is placed an annular ledge (3, made ofthe same metal as the shell A. Said ledges alternate in position withthe lining-rings B and afford a support for them, as a firmconnection'is produced between the ledges and shell by bolts or rivets.The annular ledges Care made of an equal thickness with the lining-rings13, so that a level surface is afforded on the interior of the lining atthis stage of construction.

Upon the inner surface of the iron or steel ledges O a preferably ironor steel re-enforcering D is secured on each by the screws 6, whichre-enforce rings have a plano=-convex form in vertical section, theirexterior plain surfaces being in close contact with the faces of theledges O and their convex surfaces inwardly projected. The width of there-e'n force rings is greater than that of the ledges 0, so that abearing-contact is produced between the rings D and the adjacentsurfaces of the lining-rings B. If the vertical ledges d are used, ashas been previously explained, the ends of such vertical bars should fitclosely against the ledges O and have equal width and thicknesstherewith.

Over the convex inner surface of each ring D a joint-cover E is imposed,which latter are made of plate-metal or metallic composition, which isslightly yielding in'its nature, and

Said bars cl, being preferably has a coefficient of expansion underheat, which is uniform with that of the lining-rings B. Thejoint-covering pieces E are made to bear upon the convex surface of therings D, having sufficient width to impinge upon the lining-rings B, towhich these bearing-edges are brazed or soldered, as at g in Fig. 4.Should there be vertical ledges (Z employed to separate the componentpieces of a lining-ring B, as before mentioned, these ledges are coveredby the re-enforce bars 01 and joint-covering plates 61 as shown in Fig.2, these cover-plates having a close contact with the joint-coveringpieces E, and are thereto attached by soldering or brazing, so as toproduce an acid-proof joint between the parts, and the same constructionis observed if the ring-pieces are adjoining, as at c in Fig. 2.

In large digesters it is of advantage to afford support at differentpoints to the lining of the side, top, and bottom of the chamber, and tothis end the isolated clamping-studs F are provided, the form of whichsupport, with its adjuncts, is plainly indicated in Fig. 5. The studs Fare alike, and each consists of a short cylindrical body of a lengthequal to the thickness of the lining material, having a concentricreduced bolt or rivet-body it formed on one end. inserted throughperforations made in the shell, bottom, or top of the digester at suchpoints as most need support, and are therein secured by the nuts h orother means, and upon the inner ends of the studs, which are flush withthe inner surface of the'lining, the re-enforce disks G are placed andpreferably secured thereto by the screws 71 The reenforce disksmentioned are of equal dimensions and have a nearly plano-convex form,and are of such proportionate diameter to that of the studs F as willcause them to overlap the studs and rest upon the lining of the digesterside, bottom, or top, as the case may be, and have a close contacttherewith, so that the insertion and adjustment of the screws It willbind the re-enforce disks on the lining and prevent it from bulging,while the body of the studs afford a support that will counteract asagging tendency with regard to the lining of the bottom portion A.

Upon the re-enforce disks G concavo-convex joint-covering pieces I,which are of suitable proportionate dimensions, are placed and securedby their edges to the lining B in an acid-proof manner. The supportafforded by the form of construction hereinbefore described bycompensating for the slight difference in expansion and contractionbetween the parts serves to produce durable acid-proof joints at allpoints liable to rupture from that cause.

Referring to Fig. 7, wherein the form of the joint between the lid A andthe digester-shell A is shown, it will be seen that an angle-iron ring Jis secured on the shell and affords a level top surface for the supportof the lid A The portions 7t of the studs F are,

IIC

which is bolted thereon, a re-enforce ring D, of plano-convex form,serving to seal the oiut at 2, and upon said ring a joint-covering ring1 J is imposed, which has its lower edge secured to the lining B, whilethe upper portion is extended to lie upon the horizontal face of theangle-iron ring J. The cover or lid A is also provided with a lining B,which extends to the periphery of the lid and ring J, so that a tightjoint is produced when the lid is bolted in place on the shell A.

A coating of acid and heat prc of paint or varnish is applied to theinner and outer surfaces of the digester-shell wall, bottom portion A,and lid A to protect the same from acid, gas, or steam, so that anyminute leaks from the interior will not injuriously effect thedurability of the structure.

The metallic alloy preferably used for the manufacture of the entirelining B consists of the following-named metals in about the proportionsgiven: lead, seventy-five parts; antimony, seventeen parts; tin, eightparts. To the metals mentioned a small percentage of copper should beadded, which will supplement the amount of that metal usually found inlead of commerce sold under the tradename of chemical lead. The alloyresulting from the melting together of the metals named and in theproportions about as stated will afford a hard acid-proof alloy, havinga co-efficient of expansion nearly equivalent to that of the iron orsteel shell, so that if the device is manufactured in a workmanlikemanner a durable and comparatively cheap digester will be produced.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination, with a cylindrical shell andcircular ledges riveted or bolted on the interior surface of the shell,of non-corrosive lining-rings composed of metal or alloy softer than theshell and ledges, each ring supported on a ledge, and a joint-coveringring secured at its edges over the ledges and upon the edge portions ofadjacent lining-rings, substantially as described.

2. The combination, withacylindrical shell, a series ofinwardly-projecting ledges bolted or riveted on the shell at spacedintervals,

and a series of lining-rings composed of alloy softer than the shell orledges having a coefficient of expansion and contraction nearly equalthereto, of re-enforce rings secured on the ledges and looselyoverlapping the liningrings at their adjacent edges, and joint-cow eringrings of metal or alloy similar to the lining-rings in composition andsoldered or brazed at their edges to said lining-rings, substantially asdescribed.

3. The combination, with a cylindrical shell, a series of annular spacedledges secured on the inner surface of the shell, and a series oflining-rings of alloy having their edges in contact with the ledges, ofre-enforce rings which overlap the ledges and have contact with them,and joint-covering rings of slightlyyielding metal, which are imposedupon the re-enforce rings and have their edges secured acid-tight uponthe adjacent lining rings, substantially as set forth.

at. The combination, with a cylindrical shell, interior spaced ledges ofmetal similar to the shell and riveted or bolted thereto whereonlining-rings are seated, and lining-rings of lead or alloy, which aredivided verticallyiuto sections, of vertical ledges bolted or riveted tothe interior of the shell between the edges of the lining-ring sections,re-enforce pieces secured on the circular ledges and verticalspacingledges having a plauo-convex form in cross-section and adapted toloosely bear upon the edges of the lining-ring sections, andjoint-covering rings which are adapted toloosely bear in the re-enforcebars and rings, and which are secured by their edges to ad jacentlining-rings, substantiallyas described.

5. The combination, with the cylindrical shell, conical bottom, and lidof a digester and linings therefor made of alloy, of supportingstudsaffixed to the outer wall of the digester, which project inwardly andpenetrate the lining, re-enforce disks secured on the inner ends of thestuds, and concavo-convexcoverpieces for the disks, which have theiredges secured to the lining material with acid-proof joints,substantially as set forth.

WILLIAM O. COMSTOCK. Witnesses:

WM. P. PATTON, EDGAR TATE.

